Refactor cinder/tests/test_volume.py
Refactor cinder/tests/test_volume.py

Refactor test_volume.py to remove code duplication.
- remove iterant definition of the 'expected' dict from
'test_create_delete_volume' and 'test_create_delete_snapshot'
method;
- move 'test_copy_volume_to_image_status_available',
'test_copy_volume_to_image_status_use' and
'test_copy_volume_to_image_exception' methods to new class
 CopyVolumeToImageTestCase;
- move 'test_volume_get_active_by_window' and
'test_snapshot_get_active_by_window' to new class
GetActiveByWindowTestCase;
- create base class BaseVolumeTestCase for TestCase classes.
bp cinder-tests-improvement

Change-Id: I5d3644375d321e613418ea8e544557d33401ff77

takeshineshiro/cinder,bswartz/cinder,tlakshman26/cinder-bug-fix-volume-conversion-full,j-griffith/cinder,NeCTAR-RC/cinder,hguemar/cinder,Akrog/cinder,nexusriot/cinder,cloudbau/cinder,Thingee/cinder,tlakshman26/cinder-https-changes,cloudbase/cinder,cloudbase/cinder,sasukeh/cinder,winndows/cinder,dims/cinder,tlakshman26/cinder-new-branch,ntt-sic/cinder,Paul-Ezell/cinder-1,github-borat/cinder,abusse/cinder,alex8866/cinder,potsmaster/cinder,eharney/cinder,alex8866/cinder,CloudServer/cinder,j-griffith/cinder,NetApp/cinder,petrutlucian94/cinder,CloudServer/cinder,mahak/cinder,tlakshman26/cinder-https-changes,manojhirway/ExistingImagesOnNFS,Datera/cinder,julianwang/cinder,rakeshmi/cinder,apporc/cinder,julianwang/cinder,scottdangelo/RemoveVolumeMangerLocks,ntt-sic/cinder,winndows/cinder,blueboxgroup/cinder,saeki-masaki/cinder,petrutlucian94/cinder,leilihh/cinder,bswartz/cinder,leilihh/cinder,saeki-masaki/cinder,Nexenta/cinder,spring-week-topos/cinder-week,NetApp/cinder,Hybrid-Cloud/cinder,redhat-openstack/cinder,dims/cinder,nikesh-mahalka/cinder,github-borat/cinder,apporc/cinder,scality/cinder,rakeshmi/cinder,JioCloud/cinder,rickerc/cinder_audit,Accelerite/cinder,Thingee/cinder,Akrog/cinder,openstack/cinder,Paul-Ezell/cinder-1,redhat-openstack/cinder,manojhirway/ExistingImagesOnNFS,JioCloud/cinder,eharney/cinder,hguemar/cinder,scottdangelo/RemoveVolumeMangerLocks,phenoxim/cinder,nexusriot/cinder,potsmaster/cinder,duhzecca/cinder,phenoxim/cinder,duhzecca/cinder,abusse/cinder,Accelerite/cinder,nikesh-mahalka/cinder,Thingee/cinder,tlakshman26/cinder-bug-fix-volume-conversion-full,scality/cinder,takeshineshiro/cinder,spring-week-topos/cinder-week,rickerc/cinder_audit,blueboxgroup/cinder,sasukeh/cinder,ge0rgi/cinder,Datera/cinder,openstack/cinder,mahak/cinder,NeCTAR-RC/cinder,tlakshman26/cinder-new-branch,cloudbau/cinder,Hybrid-Cloud/cinder,Nexenta/cinder